Dr. John Gottman studied couples for over thirty years and discovered the four communication qualities that could predict a couple will break up—with over 90% accuracy. Called "The Four Horsemen of the Apocalypse," these predictors have also been linked to physical illness and disease.

The Four Horsemen of the Apocalypse are:

Criticism: Not just feedback or even criticism that isn't constructive, but rather an attack on the other person's character or interests. As Gottman explains in the video above, it's an attitude one partner has in diagnosing the other person's personality defects—and even wanting to be praised for that diagnosis!

Defensiveness: Here, one person plays "the innocent victim."

Contempt: The biggest predictor of a failing relationship is contempt. One person takes on an air of superiority (thinking he/she is more intelligent, a better parent, more tidy, etc.) and looks down on and insults the other person. Gottman says this is also a predictor of infectious illnesses for the person on the receiving end. If your partner corrects your grammar while you're arguing with him/her, that's a huge red flag.

Stonewalling: The person just tunes you out and withdraws.

All couples experience conflict, but the strongest ones deal with it with more respect. If your relationship shows any of the above signs, all may not be lost, but it's a good indicator that you and your partner need to work better together to keep the relationship from falling apart.